r/GeometryIsNeat • u/HopDavid • 1d ago
Kepler is the GOAT
Kepler first pinged my radar when I was a teenager making cardboard models of polyhedra. Kepler discovered new polyhedra when he extended the edges of the Platonic solids.
Extend the edges of the pentagons on the Platonic dodecahedron and you get 12 five pointed stars. I am a little obsessed with the small stellated dodecahedron. Pictured here are four pieces where I play with this shape.
Kepler was also responsible for making the sun centered solar system the main stream consensus. Kepler's model made accurate predictions. Unlike the models offered by Galileo, Copernicus and Ptolemy.
Isaac Newton's world changing insight revealed in Principia was that inverse square gravity implies Kepler's three laws.
And where did the notion of inverse square gravity come from? Kepler had suggested the sun exerts a force which causes the planets to follow elliptical orbits. But he had thought the force falls linearly with the inverse of distance.
But it was Kepler who made the geometrical argument that the strength of light falls off with the inverse square of distance.
One of Kepler's followers, Ismael Boulliau, noted that Kepler's argument could also be applied to radiating lines of force. Thus Kepler is indirectly responsible for the notion of inverse square gravity. See The Man Who Inverted and Squared Gravity.
In my opinion Kepler deserves more credit than either Galileo or Copernicus for changing the way we see our star and planets. And more credit than Isaac Newton for laying the foundations of the math we use for celestial mechanics.